Prisms are a key component of binoculars and monoculars that help to correct the image and provide a clear and bright view. There are two types of prisms commonly used in binoculars and monoculars: Porro prisms and Roof prisms.
Porro prisms
are characterized by a distinctive Z-shaped design that allows for a longer optical path and greater image depth perception. They are typically made from a type of glass called BK7, which has a lower refractive index than other types of glass, making it less expensive to manufacture.
Roof prisms, on the other hand, have a straight-through design that allows for a more compact and streamlined binocular or monocular. They are typically made from a type of glass called BAK4, which has a higher refractive index than BK7 glass, making it more expensive but also higher quality.
K9 is another type of glass that is sometimes used in binoculars and monoculars. It has a lower refractive index than BAK4 and BK7 glass, making it less expensive, but also less effective at correcting the image and providing a clear and bright view.
In summary:
BAK4 and BK7 are the most common types of prisms used in binoculars and monoculars. BK7 is typically used in Porro prism designs, while BAK4 is used in Roof prism designs. K9 is a less expensive alternative, but is less effective at correcting the image and providing a clear and bright view.
Skip to content
